港池中波浪折射、绕射的数值模拟方法

The Numeric Modeling Method for Refraction and Diffraction of Coastal Shore Waves

从流体运动方程和动量方程出发,引入海底摩擦力和港池不完全反射作用,推导出了Berkhoff折射、绕射方程。在深海部分解析方法用精确解(含待定系数)、在复杂地形用数值离散方法求解,中间过度段用的光滑匹配将离散数值(有限元)和解析解(精确解)一同求解。通过极值问题建立泛函,利用泛函的驻定性将海岸(港湾)问题进行数值离散,建立了可行的数值模拟模型。

When deep ocean waves enter shoaling waters, their height and direction undergo significant modification due to interaction with bottom topographic variation and strong ambient current, exerting a direct and important influence on sediment transport, ship navigation, and forces on costal structures. By introducing the bottom friction and costal absorption, a mild - slope refraction and diffraction equation available for three dimension current motion is derived. Numerical disperse is used to instead of the equation in offing; In open sea, the wave is expressed by accurate functions (including unknown coefficients); These two is smoothly matched in the join line between open sea and offing, on which the unknown coefficients and the numeric equation is solved. In this paper, we derived the equation and create the numeric model for offshore waves. The model is quite useful in costal engineering applications.